The invention relates to sockets for incandescent light bulbs or lamps having a self-contained, integral current filtering device, such as a diode, capacitor, fuse or the like, preferably a diode.
The use of a diode in series with the filament of an incandescent lamp operated on alternating current increases the life of the lamp, requiring only an increase in the lamp""s wattage rating to produce a lumen output equivalent to the lamp previously used. The diode provides half wave rectified direct current to the lamp filament.
One approach to using a diode with a lamp is to install the diode in a disk shaped support which is positionable within the lamp socket with one contact surface in electrical contact with the center contact on the socket and another contact surface in electrical contact with the center contact of the lamp. The diode is positioned within the diode disk and is connected between the two contact surfaces. To facilitate proper alignment of the diode disk contact surfaces with the lamp and socket center contacts, the disk may be glued to the base of the lamp to allow the disk to travel with the lamp as it is screwed into the socket. See, for example, U.S. Pat. Nos. 4,435,671 and 4,629,943.
Diodes are also employed in series circuit with incandescent lamps in series circuits including a lamp and other electrical components, such as motors and generators, for purposes of suppressing electrical transients. Lamps typically draw a high in-rush current when initially energized, and the use of a diode in the circuit suppresses or limits the in-rush current so as not to overload the lamp and other electrical components in series with the lamp. Also, various electrical components such as motors and generators can produce large current spikes which can damage or destroy the lamp or lamps and other components in the series circuit. In this case, a diode is customarily incorporated in an electrical connector.
In other cases, the diode may simply be a free-standing element on a printed circuit board.
In all of these examples, the diode is an extraneous, separate, stand-alone element.
The object of the invention is to integrate a diode or other current filtering device within a circuit component, and more particularly within an incandescent lamp socket, to protect the lamp and the electrical components in series circuit with the lamp and to prolong the service life of the lamp.
Another object of the invention is to provide a lamp socket for miniature lamps that are employed in series circuit with other electrical components, e.g., as indicator lights for audio and video equipment, in household appliances, in gaming machines, etc.
A further object is to provide a diode containing lamp socket that, even in a miniature size, is highly resistant to damage when subjected to shock and vibration.
A still further object is to provide a diode containing lamp socket that is economical and practical to produce and convenient to use.
In accordance with the invention, a lamp socket is comprised of a body of dielectric material having a lamp base receiving opening or socket at one end thereof and a pair of spaced parallel lead chambers or channels extending from the socket opening to the other end of the body, an electrical terminal in one chamber adjacent the socket end thereof for reception of and electrical connection with one of the contact terminals on a lamp and for attachment thereto of an electrical lead, and in the other chamber, a first electrical terminal adjacent the socket end thereof for reception of and electrical connection with the other one of the contact terminals on the lamp, a second terminal spaced away from the first terminal for attachment thereto of an electrical lead, and a diode or other current filtering device disposed between, mounted on and electrically connected in series circuit with said first terminal and said second terminal.
The lamp socket of the invention is practical, economical to produce and easy to use. When employed in a circuit, the socket prolongs the service life of the lamp and protects the lamp and electrical components in series circuit therewith from detrimental electrical transients.